This invention relates to writing instruments of the type which may be retained on the forefinger of the user, thereby allowing continued use of the writing hand without interruptions necessitated by picking up and setting down a writing instrument each time it is needed.
Of key importance to the success of a finger tip writing instrument is its ability to firmly grip the forefinger of its user. Furthermore, the finger gripping mechanism should be adaptable so as to adequately grip variously sized forefingers. Also of importance is the requirement that the gripping mechanism be comfortable when applied to the forefinger of a user by not putting any appreciable stress thereon. The prior art finger tip writing instruments disclose no gripping mechanisms which simultaneously satisfy the aforementioned requirements. Traditionally, the finger insertion portion of finger tip writing instruments have consisted of thimble type members having solid walls with flattened interior surfaces. If a particular finger conformed to the shape of the thimble, an adequate grip was achieved. However, the thimble arrangement would not adequately grip fingers of other sizes and shapes.
In order to overcome the problems associated with the gripping characteristics of thimble type holders, prior art devices teach the use of holders comprising various clamping means. Although the prior art clamping holders reduce the problems associated with maintaining a firm grip, they become rather uncomfortable after continuous use for a period of time.
The prior art discloses that most proposed finger tip writing instruments were developed for use around the turn of the century. Since, at that time, ball point and felt tip pens had not been adequately developed, the prior art devices are generally limited to fountain pen type instruments. Furthermore, the prior art does not appear to disclose a finger tip writing instrument characterized by a crayon writing capability adapted for use by small children.
A significant deficiency in prior art fountain pen type instruments is that, for the most part, their ink retention capabilities are negligible. Some prior art finger tip writing instruments attempted to increase their ink retaining capabilities by the inclusion of ink reservoirs in the form of hollow walls in the body of the instrument. Although the ink retention capabilities were thereby increased, the difficulties associated with inexpensively manufacturing body members with hollow walls presented problems.
In order to carry an adequate ink supply, present day ball point pens provide a long thin tube as an ink reservoir. However, due to their relatively long length, tube type ink reservoirs would be completely inadequate with respect to a finger tip writing instrument.